An image forming apparatus includes an apparatus main body, an image carrier, a developing device, a developer housing container, and a regulating member. The developer housing container takes a posture changeable between a first posture and a second posture. The developer discharge port communicates with the developer replenishment port such that the developer is replenishable to the developing device in the first posture. The second posture locates the developer discharge port separate from the developer replenishment port and seals the developer discharge port. The regulating member allows the cover member to be closed with respect to the apparatus main body while the developer housing container takes the first posture in the apparatus main body. The regulating member regulates the cover member to be closed with respect to the apparatus main body by an interference with the developer housing container while the developer housing container takes the second posture.